In the field of contrast injection, a contrast medium of suitable indicating character (radiopacity) is introduced in a person or animal's body. To effect the introduction of the contrast medium into the patient's body, a syringe may be machine-mounted in a so-called “power injector” apparatus, with the distal end of the syringe being connected to the catheter which is introduced into the patient.
Injectors are devices that expel fluid, such as contrast media, from a syringe and through a tube into a person or animal. The injectors are provided with an injector unit, usually adjustably fixed to a stand or support, and have a drive ram that couples to the plunger of the syringe to drive it forward to expel fluid into the tube, or to drive the plunger rearward to draw fluid into the syringe to fill it. Usually the syringe is a disposable replacement type.
U.S. Pat. No. 5,300,031 (“the '031 patent) discloses a front-loading injector (“the '031 injector”.) The '031 injector has a pressure jacket mounted to its front face for receiving a closely-fitting syringe. A syringe having an open back end is inserted into the pressure jacket and coupled to the open end of the pressure jacket by a rotating motion. This same rotating motion causes the plunger in the syringe to couple to the end of the ram. The pressure jacket supports the side walls of the syringe against injection pressure during operation of the injector. After an injection, a reverse rotating motion unlocks the syringe from the pressure jacket and releases the plunger from the ram, so the syringe can be removed and replaced.
One problem with the '031 injector is that the pressure jacket limits the types of syringes that can be used with the '031 injector. Syringes that do not need pressure jackets cannot be utilized. Another problem with the '031 injector is that the ram-plunger connection comprises complex moving parts that require periodic maintenance and are prone to needing repair to function properly. A third problem with the '031 injector is that the combination pressure jacket and syringe make it difficult to view the contrast media inside the syringe, for example to determine whether air bubbles are present within the syringe.
U.S. Pat. No. 6,080,136 discloses a front-loading syringe and adapter for a contrast injector. The syringe comprises a one-piece barrel and open back end such that the syringe can be front loaded onto an injector equipped with the disclosed adapter. The syringe barrel is transparent and does not require the use of a pressure jacket for its intended use. Therefore, the contrast media inside the syringe can be easily viewed and inspected for the presence of air bubbles.
An additional problem with injectors and syringe adapters that attach a syringe via insertion and rotation of the syringe into the adapter or injector is that the syringe could rotate in the injector or adapter and cause the syringe to not be fully installed during an injection, which is more likely to result in the syringe being misaligned, which could result in fluid spillage.
Accordingly, the present invention is hereby submitted.